import isFunction from 'lodash.isfunction';

// https://github.com/twbs/bootstrap/blob/v4.0.0-alpha.4/js/src/modal.js#L436-L443
export function getScrollbarWidth() {
  let scrollDiv = document.createElement('div');
  // .modal-scrollbar-measure styles // https://github.com/twbs/bootstrap/blob/v4.0.0-alpha.4/scss/_modal.scss#L106-L113
  scrollDiv.style.position = 'absolute';
  scrollDiv.style.top = '-9999px';
  scrollDiv.style.width = '50px';
  scrollDiv.style.height = '50px';
  scrollDiv.style.overflow = 'scroll';
  document.body.appendChild(scrollDiv);
  const scrollbarWidth = scrollDiv.offsetWidth - scrollDiv.clientWidth;
  document.body.removeChild(scrollDiv);
  return scrollbarWidth;
}

export function setScrollbarWidth(padding) {
  document.body.style.paddingRight = padding > 0 ? `${padding}px` : null;
}

export function isBodyOverflowing() {
  return document.body.clientWidth < window.innerWidth;
}

export function getOriginalBodyPadding() {
  return parseInt(
    window.getComputedStyle(document.body, null).getPropertyValue('padding-right') || 0,
    10
  );
}

export function conditionallyUpdateScrollbar() {
  const scrollbarWidth = getScrollbarWidth();
  // https://github.com/twbs/bootstrap/blob/v4.0.0-alpha.6/js/src/modal.js#L433
  const fixedContent = document.querySelectorAll('.fixed-top, .fixed-bottom, .is-fixed, .sticky-top')[0];
  const bodyPadding = fixedContent ? parseInt(
    fixedContent.style.paddingRight || 0,
    10
  ) : 0;

  if (isBodyOverflowing()) {
    setScrollbarWidth(bodyPadding + scrollbarWidth);
  }
}

export function mapToCssModules(className, cssModule) {
  if (!cssModule) return className;
  return className.split(' ').map(c => cssModule[c] || c).join(' ');
}

/**
 * Returns a new object with the key/value pairs from `obj` that are not in the array `omitKeys`.
 */
export function omit(obj, omitKeys) {
  const result = {};
  Object.keys(obj).forEach((key) => {
    if (omitKeys.indexOf(key) === -1) {
      result[key] = obj[key];
    }
  });
  return result;
}

/**
 * Returns a filtered copy of an object with only the specified keys.
 */
export function pick(obj, keys) {
  const pickKeys = Array.isArray(keys) ? keys : [keys];
  let length = pickKeys.length;
  let key;
  const result = {};

  while (length > 0) {
    length -= 1;
    key = pickKeys[length];
    result[key] = obj[key];
  }
  return result;
}

let warned = {};

export function warnOnce(message) {
  if (!warned[message]) {
    /* istanbul ignore else */
    if (typeof console !== 'undefined') {
      console.error(message); // eslint-disable-line no-console
    }
    warned[message] = true;
  }
}

export function deprecated(propType, explanation) {
  return function validate(props, propName, componentName, ...rest) {
    if (props[propName] !== null && typeof props[propName] !== 'undefined') {
      warnOnce(`"${propName}" property of "${componentName}" has been deprecated.\n${explanation}`);
    }

    return propType(props, propName, componentName, ...rest);
  };
}

export function DOMElement(props, propName, componentName) {
  if (!(props[propName] instanceof Element)) {
    return new Error(
      'Invalid prop `' + propName + '` supplied to `' + componentName +
      '`. Expected prop to be an instance of Element. Validation failed.'
    );
  }
}

export function getTarget(target) {
  if (isFunction(target)) {
    return target();
  }

  if (typeof target === 'string' && document) {
    const selection = document.querySelector(target);
    if (selection === null) {
      return document.querySelector(`#${target}`);
    }
    return selection;
  }

  return target;
}


/* eslint key-spacing: ["error", { afterColon: true, align: "value" }] */
// These are all setup to match what is in the bootstrap _variables.scss
// https://github.com/twbs/bootstrap/blob/v4-dev/scss/_variables.scss
export const TransitionTimeouts = {
  Fade:     150, // $transition-fade
  Collapse: 350, // $transition-collapse
  Modal:    300, // $modal-transition
  Carousel: 600, // $carousel-transition
};

// Duplicated Transition.propType keys to ensure that Reactstrap builds
// for distribution properly exclude these keys for nested child HTML attributes
// since `react-transition-group` removes propTypes in production builds.
export const TransitionPropTypeKeys = [
  'in',
  'mountOnEnter',
  'unmountOnExit',
  'appear',
  'enter',
  'exit',
  'timeout',
  'onEnter',
  'onEntering',
  'onEntered',
  'onExit',
  'onExiting',
  'onExited',
];

export const TransitionStatuses = {
  ENTERING: 'entering',
  ENTERED:  'entered',
  EXITING:  'exiting',
  EXITED:   'exited',
};

export const keyCodes = {
  esc:   27,
  space: 32,
  tab:   9,
  up:    38,
  down:  40,
};

export const PopperPlacements = [
  'auto-start',
  'auto',
  'auto-end',
  'top-start',
  'top',
  'top-end',
  'right-start',
  'right',
  'right-end',
  'bottom-end',
  'bottom',
  'bottom-start',
  'left-end',
  'left',
  'left-start',
];